Re: [PATCH v1] mm: Consistently use current->mm in mm_get_unmapped_area()

[Oscar Salvador <osalvador@suse.de>]

On Fri, Oct 03, 2025 at 04:53:04PM +0100, Ryan Roberts wrote:
> mm_get_unmapped_area() is a wrapper around arch_get_unmapped_area() /
> arch_get_unmapped_area_topdown(), both of which search current->mm for
> some free space. Neither take an mm_struct - they implicitly operate on
> current->mm.
> 
> But the wrapper takes an mm_struct and uses it to decide whether to
> search bottom up or top down. All callers pass in current->mm for this,
> so everything is working consistently. But it feels like an accident
> waiting to happen; eventually someone will call that function with a
> different mm, expecting to find free space in it, but what gets returned
> is free space in the current mm.
> 
> So let's simplify by removing the parameter and have the wrapper use
> current->mm to decide which end to start at. Now everything is
> consistent and self-documenting.
> 
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>

I think it looks cleaner:

Reviewed-by: Oscar Salvador <osalvador@suse.de>


-- 
Oscar Salvador
SUSE Labs